AIR CONDITIONING SYSTEM > Air Conditioning Compressor Magnetic Clutch Circuit

for Preparation Click here


DESCRIPTION

The A/C amplifier sends a magnetic clutch ON command signal to the ECM through the BEAN line and CAN line. Then the ECM turns the A/C COMP relay on to turn the magnetic clutch on.

WIRING DIAGRAM


E109711E01


INSPECTION PROCEDURE

1.INSPECT FUSE (A/C COMP)

  1. Remove the A/C COMP fuse from the engine room No. 2 junction block.

  1. Measure the resistance of the fuse.


Standard resistance:

Tester Item
Condition
Specified Condition
A/C COMP fuse
Always
Below 1 Ω



NG
REPLACE FUSE
OK


2.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and push the intelligent tester main switch on.

  1. Select the item below in the Data List, and read the displays on the intelligent tester.

    ECM: 
    Item
    		Measurement Item / Display
    (Range)
    		Normal Condition
    		Diagnostic Note
    A/C Magnetic Clutch Relay
    (A/C Mag Clutch)
    		A/C Magnetic Clutch Relay / OFF, ON
    		ON: A/C magnetic clutch ON
    OFF: A/C magnetic clutch OFF
    		-

    OK:
    The display is the condition.



OK
REPLACE ECM
NG


3.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

  1. Select the item below in the Active Test, and read the displays on the intelligent tester.

    A/C amplifier: 
    Item
    		Test Details / Display
    (Range)
    		Diagnostic Note
    Magnetic Clutch Relay
    (A/C Mag Clutch)
    		Magnetic Clutch Relay / OFF, ON
    		-



OK
REPLACE A/C AMPLIFIER
NG


4.INSPECT RELAY (A/C COMP)
B060778E04

  1. Remove the A/C COMP relay from the engine room No. 2 relay block.

  1. Measure the resistance of the relay.

    Standard resistance:
    Tester Connection
    		Specified Condition
    3 - 5
    		10 kΩ or higher
    3 - 5
    		Below 1 Ω
    (when battery voltage is applied to terminals 1 and 2)



NG
REPLACE RELAY
OK


5.INSPECT A/C COMPRESSOR
E105415E08

  1. Disconnect the E46 A/C compressor connector.

  1. Measure the resistance of the connector.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1 (MG+) - Body ground
    		Always
    		Below 1 Ω

  1. When connector terminal 1 (MG+) is connected to the positive (+) battery terminal, and the body ground is connected to the negative (-) battery terminal, check that the following occurs: 1) the magnetic clutch's operating sound is emitted, and 2) the magnetic clutch's hub and rotor lock.



NG
REPLACE A/C COMPRESSOR
OK


6.CHECK WIRE HARNESS (ENGINE ROOM NO. 2 RELAY BLOCK - A/C COMPRESSOR)
E108194E02

  1. Remove the A/C COMP relay from the engine room No. 2 relay block.

  1. Disconnect the E46 A/C compressor connector.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    Relay block A/C COMP relay terminal 3- E46-1 (MG+)
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


7.CHECK WIRE HARNESS (ENGINE ROOM NO. 2 RELAY BLOCK - ECM)
E108195E02

  1. Remove the A/C COMP relay from the engine room No. 2 relay block.

  1. Disconnect the A7 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    Relay block A/C COMP relay terminal 2 - A7-11 (ACMG)
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE